Understanding Urinary Incontinence

Sep 22, 2024

Urinary Incontinence Lecture Notes

Introduction

  • Topic: Urinary Incontinence
  • Part of Clinical Medicine section
  • Encourage engagement: like, comment, subscribe to support the community
  • Membership benefits: access to notes, illustrations, quizzes, exam prep programs

Definition of Urinary Incontinence

  • Undesirable involuntary loss of urine.
  • Types of incontinence:
    • Stress Incontinence
    • Urge Incontinence
    • Overflow Incontinence
    • Mixed Incontinence (not discussed)

Types of Urinary Incontinence

1. Stress Incontinence

  • Concept: Increased intra-abdominal pressure leading to urine leakage.
  • Mechanism:
    • High intra-abdominal pressure compresses the bladder, increasing bladder pressure.
    • Urine leaks when bladder pressure exceeds pelvic floor muscle strength.
  • Common Triggers:
    • Coughing, sneezing, laughing (transient rises in pressure).
  • Risk Factors:
    • Obesity
    • Pregnancy
    • Multi-parity (multiple childbirths)
    • Menopause (low estrogen levels leading to weak pelvic muscles)
  • Key Findings:
    • Incontinence after coughing, laughing, or sneezing.
    • History of obesity, pregnancy, multi-parity, or menopause.

2. Urge Incontinence

  • Concept: Loss of urine with a strong desire to urinate.
  • Mechanism:
    • Increased activity of the detrusor muscle causing high bladder pressure.
  • Causes:
    • Neurological dysfunction (e.g., Parkinson's disease, stroke, spinal cord injuries).
    • Inflammation (e.g., urinary tract infections).
  • Key Findings:
    • Loss of urine preceded by a strong urge to urinate.
    • Frequent nocturia.

3. Overflow Incontinence

  • Concept: Continuous dribbling with incomplete bladder emptying.
  • Mechanism:
    • Decreased detrusor muscle activity or bladder outlet obstruction.
  • Common Causes:
    • Neurological dysfunction (e.g., multiple sclerosis, diabetes, spinal cord injuries).
    • Medications (especially anticholinergics).
    • Bladder outlet obstruction (e.g., benign prostatic hyperplasia).
  • Key Findings:
    • Feeling of incomplete bladder emptying.
    • Dribbling of urine.

Complications of Urinary Incontinence

Overflow Incontinence Complications

  1. Urinary Tract Obstruction
    • Can lead to hydronephrosis (enlarged kidney) and post-renal AKI due to high bladder pressure.
  2. Urinary Tract Infection (UTI)
    • Increased risk due to urinary retention allowing bacterial colonization.
    • Symptoms: urgency, frequency, dysuria.
  3. Skin Breakdown
    • Continuous urine leakage can cause dermatitis, cellulitis, and pressure ulcers.

Diagnostic Approach

  • Primarily clinical diagnosis; lab tests and imaging often unnecessary.
  • Stress Incontinence:
    • Positive bladder stress test (Q-tip test).
  • Urge Incontinence:
    • Rule out UTIs with urinalysis.
  • Overflow Incontinence:
    • Measure post-void residual (should be <200 mL to rule out retention).
    • Digital rectal exam for prostate size.

Treatment Approaches

1. Stress Incontinence

  • Strengthening Pelvic Floor: Kegel exercises.
  • Hormonal Therapy: Estrogen creams for post-menopausal women.
  • Supportive Devices: Vaginal pessaries.
  • Surgical Options: Mid-urethral sling procedure.

2. Urge Incontinence

  • Bladder Training: Good voiding schedule.
  • Medications:
    • Anticholinergics (oxybutynin, tolteridine, solifenacin).
    • Sympathomimetics (mirabegron) to reduce detrusor contractions.
    • Sacral nerve stimulation for severe cases.

3. Overflow Incontinence

  • Immediate Management: Catheterization to empty bladder.
  • Medications:
    • Discontinue anticholinergics if causing overflow.
    • Alpha-1 blockers for BPH (e.g., tamsulosin).
    • Surgical intervention (e.g., TURP for BPH).

Conclusion

  • Urinary incontinence has various types, causes, and treatment approaches.
  • Understanding the pathophysiology helps in diagnosis and treatment.
  • Importance of patient history and symptoms in determining type and management.